So, in the process of setting up my new darkroom I am moving from stainless steel inversion tanks to a Jobo CPP2 with lift. I have used a Jobo before and am familiar with its operation, though this particular Jobo is new to me. I have some Pyrocat HD that I would like to test for development time. For various reasons, I would prefer to shoot at box speed and adjust development to match. I am however a little confused on how to do this. My plan was to shoot a normal scene say 4 times, then process each one for a different amount of time and go with the one that looks good. I don't have a densitometer or sensitometer. I'm not exposing using the zone system. I see that Richard Ritter offers a service - Film testing - but I'm not sure if this would help me or how I would use it. I guess what I need is a beginner's tutorial on determining development speed.